We are relatively new to making and using terra sig for our pit fired ware. We are curious to know how long a batch remains "good". We have not dried down the sig, as others suggest, but have kept it (two different batches) in sealed, covered containers. The older batch is about 4 yrs. old, the other is about 2.5 yrs. old. The newer batch has settled into two layers: a water clear upper layer and a bottom silty layer, while the older batch's top layer is less clear, but the bottom layer is similar to the first. I don't know the S.G. of either batch, but when fresh, it was approx. 1.15.
Are we better off making new sig or might we use what we have?
Any insight, comments, and or suggestions are greatly appreciated.